Electrical coils are used in many industrial products. One possible application is for example the use of an electrical coil as a rotational speed sensor. In industrial applications, the available space for the installation of such electrical coils, in particular rotational speed sensors, is often small. It is therefore a technical challenge to accommodate the electrical coil, together with its electrical contacting, in the smallest constructive space and to ensure, over the lifespan of its use, a reliable electrical contact between the electrical terminals and the coil.
As a rule, electrical coils are made up of a defined number of windings of a wire around a holding body. As an electrical wire, frequently a thin metal wire is used, and particularly often so-called enameled copper wire is used. This electrical wire is surrounded by an electrically insulating layer of enamel, also referred to hereinafter as an insulating layer, in such a way that no electrical short-circuit arises between the wire windings that contact each other. The insulating layer used is often made up of a protective enamel that in many cases has a thickness of from 1 to 5 μm. In order to enable operation of the finished wound coil, the wire ends of the coil must be reliably electrically contacted, and for this purpose in particular the insulating layer has to be reliably penetrated. For this purpose, in many cases thermal contacting methods are used, such as welding or soldering.
Such thermal contacting methods require an additional working process that entails increased installation costs and process costs.
In addition, it is often difficult in the available narrow constructive space to ensure a reliable electrical contacting using the known thermal contacting methods.
German Published Patent Application No. 10 2004 002 935 describes an electrical connection system for producing an ignition coil that is intended to replace currently used contacting methods for connecting thin enameled wires in ignition coils with a so-called “cold” contacting. However, such an electrical connection system is preferably suitable for an end-face contacting.